The statements in this section merely provide background information related to the present disclosure and do not constitute prior art. Further, as the statements in this section describe a technology corresponding to the background information, the contents of the background art are incorporated into the method and apparatus for encoding/decoding according to some embodiments of the present disclosure. Video compression technology experts gathered by MPEG (moving picture experts group) and VCEG (video coding experts group) have formed their joint team called JCT-VC (joint collaborative team on video coding). JCT-VC is working for the standardization of the proposed standard called HEVC (high efficiency video coding) toward the development of a new high-quality, high-performance and high-efficiency video compression technology with improved compression performance of about 50% or more than the state of H.264/AVC (advanced video coding). HEVC has been started with the aim of achieving a high quality/high performance compression technology with a compression rate that has been improved over the technology of the existing H.264/AVC and adopted various methods of encoding, leading to a significant development in terms of improving the image quality and performance than the existing standard technology.
Summary
In accordance with some embodiments of the present disclosure, an apparatus for encoding images comprises a predictor, a subtractor, a transformer, a quantizer and a bitstream generator. The predictor is configured to determine a prediction unit (PU) mode among a plurality of PU modes indicating types of partition of a current coding unit (CU) into one or more prediction units (PUs), and generate a predicted block of the current CU by performing an intra prediction or an inter prediction for each PU of the determined PU mode, wherein a size of the current CU is 2N×2N, and the plurality of PU modes includes 2N×hN or hN×2N PU mode in which the current CU is partitioned into PUs respectively having a size of 2N×hN or hN×2N, h being a fractional number smaller than 1. The subtractor is configured to subtract the predicted block from the current CU to generate a residual block. The transformer is configured to transform the residual block into a frequency domain to generate one or more transform blocks. The quantizer is configured to quantize the transform blocks. And the bitstream generator is configured to encode the quantized transform blocks and information on the determined PU mode into a bitstream.
In accordance with some embodiments of the present disclosure, an apparatus for decoding images comprises a decoder, an inverse quantizer, an inverse transformer, a predictor and an adder. The decoder is configured to decode one or more quantized transform blocks from a bitstream and extract PU mode information indicating a prediction unit (PU) mode of a current coding unit (CU) among a plurality of PU modes relating to types of partition of the current CU into PUs, wherein a size of the current CU is 2N×2N and the plurality of PU modes include 2N×hN or hN×2N PU mode in which the current CU is partitioned into PUs respectively having a size of 2N×hN or hN×2N, h being a fractional number smaller than 1. The inverse quantizer is configured to inversely quantize the quantized transform blocks to generate transform blocks. The inverse transformer is configured to inversely transform the transform blocks to reconstruct a residual block of the current CU. The predictor is configured to generate a predicted block of the current CU by predicting each PU within the current CU based on the PU mode information. And the adder is configured to add the reconstructed residual block and the generated predicted block to thereby reconstruct the current CU.